1. Amino acid-dependent sugar transport systems have been identified in various species of Fusobacteria. 2. The phosphoenolpyruvate (PEP): dependent sucrose phosphotransferase system has been found in F. mortiferum. The first purification of the ATP-dependent fructokinase from this organism has been achieved, and the N-terminal has been determined. 3. Sucrose 6-phosphate hydrolase has been purified to homogeneity from Lactococcus lactis, and the structural gene (scrA) has been localized on the chromosomally-encoded transposon, Tn5306. 4. Fructokinase from L.lactis has also been purified to homogeneity, and the scrK gene is also localized on transposon Tn5306, close to scrA. 5. Transposon Tn5306 is the first "metabolic" transposon to be described in lactic acid bacteria. This large (~50-100kb?) fragment of 'mobile' DNA encodes genes for N5-(CE)ornithine synthase, sucrose transport and catabolism, nisin synthesis and resistance, and a transposase gene.